Semen from [male] fowls of a randombred line and a line selected for increased fertility duration of thawed semen (12 [male][male] per line) was diluted in Lake's diluent with or without glycerol. Half of each sample was frozen to -196 degrees C at -6 degrees per min, and thawed next morning. All semen was then treated with ethidium bromide (fluorescent stain) solution to stain DNA in dead and damaged spermatozoa, then treated with digitonin to make live spermatozoa permeable to the stain. Show moreSemen from [male] fowls of a randombred line and a line selected for increased fertility duration of thawed semen (12 [male][male] per line) was diluted in Lake's diluent with or without glycerol. Half of each sample was frozen to -196 degrees C at -6 degrees per min, and thawed next morning. All semen was then treated with ethidium bromide (fluorescent stain) solution to stain DNA in dead and damaged spermatozoa, then treated with digitonin to make live spermatozoa permeable to the stain. Percentages of dead spermatozoa were as follows for fresh semen from [male][male] of the selected and non-selected lines and frozen semen from the 2 lines: semen in diluent without glycerol, 25.5+or-7.1, 25.3+or-3.9, 88.3+or-9.1 and 89.4+or-4.0 resp.; semen in diluent with glycerol, 28.5+or-6.6, 26.5+or-4.5, 52.3+or-8.3 and 49.4+or-5.5; glycerolised semen after removal of glycerol by redilution and centrifugation, 24.6+or-4.6, 23.3+or-2.6, 44.7+or-7.9 and 46.7+or-6.7.. Show less